Hot-air furnace.



` J. PREUSS.

HOT AIR FURNAGB.

, APPLIGATION FILED 11111.31. 1910.

983,566. Patented 111811.11911.

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J. PREUSS. HOT AIR PURNAGB.

APPLOA'IION FILED JAN. 3l, 1910.

PatentedV Feb. 7, 191 1.

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JOI-IN PREUSS, OF CHICAGO, ILLINOIS.

HOT-AIR FURNACE.

Specification of Letters Patent.

Patented Feb. *7, 1911.

Application 4filed January 31, 1910. Serial No. 541,030.

To all whom it may concern:

Be it known that I, JOHN Pnnuss, a citizen of the United States,residing at Chilago, county of Cook, and State of Illinois, haveinvented certain new and useful Improvements in Hot-Air Furnaces, ofwhich the following is a specification.

My invention relates to hot-air furnaces and has for its object theproduct-ion of a device of this character which will be of strong,durable and economical construction and efficient in operation.

Other objects will appear hereinafter.

lith .these objects in view my invention consists generally in a furnacecharacterized as above mentioned and wherein the furnace heat-radiatingsurface will be increased to a maximum and further wherein the heatedgases arising from the furnace lire-box will be thoroughly utilizedbefore being exhausted to heat said radiating` surface.

My invention further consists in the provision in the hot-air chamber ofthe furnace of means whereby the cold air or gases introduced thereinwill be caused to pass through an elongated heating passage beforereaching the distributing portion of said chamber', and whereby athorough heating of said gases before delivery to the registers employedin connection with the furnace will be effected.

My invention further consists in certain details of construction andarrangement of parts which will be hereinafter fully described and moreparticularly pointed out in the appended claim.

My invention will be more readily understood by reference to theaccompanying drawings forming a part of this specification, and inwhich,

Figure 1 is a central vertical section of a hot-air furnace embodyingthe preferred form of my invention, and Figs. 2 and 3 are horizontalsections thereof taken on Vline m-:r and y-g/ respectively of Fig. 1.

Referring now to the drawings 1 indicates a cylindrical shell or housingmounted upon a suitable annular base 2. Centrally arranged within theshell 1 is an ash-box 3 provided with a hinged door 4t. 5 indicatesgrate bars.

6 is the lire-box provided with a hinged door 7, said lire-box andash-box being acccssible from without, as clearly illustrated in Fig. 3.Spacing bars 8 are preferably provided to effect a rigid connection andopposite relative positioning of said lire-box and shell. Co-axiallyarranged within the shell 1 the lower end thereof being supported uponthe lire-box 6, as shown, is a tubular core member 9 open at its upperend. Provided adjacent the lower extremity of the lateral wall of saidcore is a plurality of` openings 10. Arranged within said core isasnugly itting worm 11 co-extensive in length therewith and whereby ahelically extending passage 12 is formed therethrough. Arranged in theannular space intervening the adjacent surfaces of the shell 1 and core9 is a helically extending partition 13 whereby a helically extendingpassage 14 is formed therein. Arranged in said passage is a helicalsmoke pipe 15 communicating at its lower extremity with the fire-box, asshown, and having its upper extremity projecting exteriorly andcommunicating with the out side atmosphere. The passages 12 and 14communicate at their upper extremities with a hot-air distributingchamber 16 provided at the upper extremity of the shell 1.

17 are the usual conduits by means of which the heated gases areconveyed to the registers employed in connection with the furnace.Provided in the shell 1 adjacent the lower extremity thereof is aplurality of air inlets 18.

Vith the provision of a furnace of a construction as set forth cold airwill be admitted to the interior of the shell 1 through the openings 18.This air will rise in said shell first contacting the heated exteriorsurfaces of the ash-box and fire-box and thence entering the passage 14and passing upwardly therethrough to the chamber 16. Some of the airadmitted to said passage 14. will pass through the openings 10 to theinterior of the core 9 wherein they will be conveyed through the passage12 and thence to the chamber' 16. Upon entering the shell 1 the air,because of its contact with the heated surfaces of the ash-box andlire-box, will evidently be heated to a considerable extent. In itspassage through the passages 12 and 14 it will again be subjected t-othe heated surfaces of the smoke pipe 15 and the surfaces positionedadjacent thereto which, because of such proximity to said pipes, arealso in a heated condition, and whereby the heated condition thereof isgreatly increased. Thus the gas entering the chamber 16 and which isconveyed through the pipe 17 will vbe in a highly heated condition, suchmaxithe preferable form of my furnace I do notY wish to be limitedthereto as there might be various changes made in the details ofconstruction and arrangement of parts described without departing fromthe spirit of' the invention comprehended Within the scope of theappended claim.

Having described my invention what I claim as new and desire to secureby Letters Patent is:

A hot-air furnace comprising an outer cylindrical shell, a fire-boxarranged centrally within said shell at the lower end thereof, a tubularcylindrical core coaXially arranged within said shell above saidfire-box terminating below the top of said shell and forming an'annularchamber in the same, said core being open at its upper and lower endsand communicating atboth ends With said annular chamber, a helicallyextending partition in said annular chamber forming a similarlyextending passage therethrough, a smoke pipe arranged in said passagehaving its lower end communicating With said fire-box, said smoke pipeextending substantially from one adjacent convolution of the helicalpartition to the other adjacent convolution forming passage Ways eachside of the smoke pipe, a snugly fitting Worm arranged within said core,a hot-'air distributing chamber at the upper end of said shellcommunicating with said air passage and the upper end of said core, saidshell being provided with air openings adjacent its lower extremity,hotair conduits communicating with said distributing chamber and theportion of said shell surrounding said helical partition being formed ofhinged members, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of tWo subscribing Witnesses.

JOHN PREUSS.

Witnesses JANET E. HOGAN, JOSHUA R. H. Por'rs.

